JPS61228158A - Three axes driving unit - Google Patents

Abstract

PURPOSE:To permit the correct position control by connecting an outer spherical shell on the fixed side and the inner spherical shell on the driven side through a gimbal mechanism and installing actuators which revolve around three axes on the inner spherical shell. CONSTITUTION:An inner spherical shell 5 installed onto the shaft lever 2 on the driven side is accommodated into an outer spherical shell 4 installed onto the shaft lever 1 on the fixed side so as to be revolved relatively. The outer and inner spherical shells 4 and 5 are connected through a gimbal mechanism 6 so as to be revolved around three axes crossing at right angles each other. Rotary actuators 14-16 consisting of three motors, etc. for deceleration- revolving the inner spherical shell 5 through a frictional wheel 17 around three axes are installed onto the outer spherical shell 4 side, and said frictional wheel 17 is attached onto the inner spherical shell 5 through a hole 18 formed onto the outer spherical shell 4.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Field of Application 1] The present invention relates to a three-axis drive unit used in joints of robot arms, etc.

[Prior Art] The present inventors previously proposed a three-dimensional motor having three degrees of freedom as one of this type of drive units (Japanese Patent Application No. 80058/1982).

The three-dimensional motor described above has windings that generate rotating magnetic fields around three mutually orthogonal axes, and rotates in any direction within a stator that can generate a composite rotating magnetic field in any direction. It is constructed by providing a rotor that is supported in a rotor manner.

However, since this three-dimensional motor is configured as a synchronous motor or an induction motor, its structure and control system are complicated, and since it is a direct drive type, it is difficult to drive at high torque. have.

rProblems to be Solved by the Invention J The purpose of the present invention is to provide a method (3) that is simple in structure and control, capable of high torque drive, and capable of accurate positioning control.
The purpose of the present invention is to provide a shaft drive unit.

[Means for Solving the Problems] In order to achieve the above object, the three-axis drive unit of the present invention has an inner spherical shell attached to the driven side axis in an outer spherical shell attached to the fixed side axis lever. A spherical shell is accommodated in a relatively rotatable manner, and the outer spherical membrane and inner spherical shell are connected via a gimbal mechanism that is rotatable around three orthogonal axes, and a friction wheel is installed on the outer spherical shell side. Three rotary actuators are installed to decelerate and rotate the inner spherical shell around the three axes through the gimbal mechanism, and the rotation angle and rotational angular velocity are detected and input to the actuators. It is constructed by providing rotation measurement means for feeding back to each side.

[Function] In the three-axis drive unit of the present invention having the above configuration,
When each actuator is driven, the inner spherical shell rotates synthetically around the X-axis, Y-axis, and X-axis according to the driving force components of these seven actuators, and is driven in an arbitrary direction. Therefore, the shaft rod on the driven side attached to the inner spherical shell can also be driven and displaced to an arbitrary position together with the inner spherical shell.

The rotational angle and rotational angular velocity of the inner spherical shell are detected by the rotation measuring means, and are fed back to the control device on the input side of the 7 cutuator, whereby the inner spherical shell, that is, the shaft rod on the driven side, can be moved to an arbitrary position. accurately positioned.

Further, the torque of the actuator is amplified by the reduced rotation of the inner spherical shell by the friction wheel, thereby achieving high torque drive.

[Effects of the Invention] According to the present invention having the above-mentioned configuration, an existing rotary actuator can be used, so the structure becomes very simple and compact, and the inner spherical shell can be moved through a friction wheel. Because it is configured to rotate at a reduced speed, high-torque drive is possible.Furthermore, by measuring the rotation angle and rotational angular velocity around the three axes of the driven side shaft rod with a built-in rotation measurement means, accurate positioning is possible. can be controlled.

[Embodiment 1] Hereinafter, an embodiment of the present invention will be described in detail based on the drawings.A three-axis drive unit of the present invention schematically shown in FIG. The inner spherical shell 5 is attached to the shaft rod 2 on the driven side within the outer spherical membrane 4 attached to the
are housed so as to be relatively rotatable, and these outer bulb membrane 4 and inner bulb fa5
The two spherical shells 4.5 are connected via a gimbal mechanism 6 that enables rotation about three axes perpendicular to each other, that is, the X-axis, the Y-axis, and the X-axis. Opening 7 for allowing relative displacement with the shaft rod attached to the spherical shell
, 8 are provided.

The gimbal mechanism 6 has substantially arc-shaped support arms 11 and 12 rotatably attached to arms 9 and 10 that are integrated perpendicularly to the X-axis direction and the Y-axis direction, and one of the support arms 11 The shaft rod 2 on the driven side is mounted rotatably around the X-axis with the shaft rod 2 on the driven side facing in the X-axis direction, and the shaft rod 1 on the fixed side is fixedly mounted on the other support arm 12. ing.

As shown in FIG. 2, on the outer sphere membrane 4 side, there are three motors etc. that rotate the inner sphere 5a5 around the X axis, the Y axis, and the X axis at a reduced speed through the friction wheel 17. The friction wheel 17 attached to the rotating shaft of each actuator is attached to the outer spherical membrane 4.
The inner spherical shell 5 is brought into contact with the inner spherical shell 5 through a hole 18 provided in the inner spherical shell 5.

In addition, in order to control the positioning of the inner spherical shell 5, that is, the shaft rod 2 on the driven side, to an arbitrary position, the
Rotation measuring means 18 to 21 each consisting of an angle detector 22 that detects the rotation angle of each axis and an angular velocity detector 23 that detects the rotational angular velocity are provided in the rotating part around the axis, The measurement signal of the actuator 14
It is configured to feed back to the input side of ~1B, that is, a control device (not shown).

The rotation measuring means 18 to 21 can be configured by, for example, a potentiometer, a resolver, or the like.

In the three-axis drive unit having the above configuration, the outer bulb membrane 4
When each of the above actuators 14 to 1B is driven, the inner spherical shell 5 rotates synthetically around the X-axis, Y-axis, and X-axis according to the driving force components of these actuators, and is driven in an arbitrary direction. Therefore, the shaft rod 2 on the driven side attached to the inner spherical shell 5 can also be driven and displaced to an arbitrary position together with the inner spherical shell 5.

The rotation angle and rotation angular velocity around the three axes of the inner spherical shell 5, that is, the driven shaft rod 2, are detected by rotation measurement means 19 to 21 built into the gimbal mechanism 6, and are used to control each actuator 14 to 1B. feedback to the device,
Thereby, the driven side shaft rod 2 can be accurately positioned at any desired position.

Further, due to the deceleration rotation of the inner spherical shell 5 by the friction wheel 17, the torque of each of the seven cutuators 14 to 1B is amplified and transmitted to the inner spherical shell 5, thereby performing high torque drive.

[Brief explanation of drawings]

FIG. 1 is a partially cutaway perspective view schematically showing an embodiment of the present invention, and FIG. 2 is a side view showing how the actuator is attached. lΦ・Stationing side shaft rod, 2. Fist driven side shaft rod, 4-・Outer bulb membrane, 5. Inner bulb shell. 8・φ gimbal mechanism, 14.15, 18・actuator, 17・11 friction wheel, 19.20, 21・φ rotation measurement means.

Claims (1)

[Claims] 1. The inner spherical shell attached to the driven side shaft is accommodated in the outer spherical shell attached to the fixed side shaft so as to be relatively rotatable, and these outer spherical shell and inner spherical shell are orthogonal to each other. Three rotary actuators are connected via a gimbal mechanism rotatable around three axes, and three rotary actuators are installed on the outer spherical shell side to decelerate and rotate the inner spherical shell around the three axes via a friction wheel. A three-axis drive unit characterized in that rotation measuring means for detecting rotation angles and rotation angular velocities of the rotation parts around the three axes of the gimbal mechanism and feeding them back to the input side of the actuator is provided.